CN101673520B - Liquid crystal display (LCD) device and image signal processing method - Google Patents

Abstract

The invention discloses a liquid crystal display (LCD) device and an image signal processing method applied to the LCD device. The LCD device comprises a decoding module, a dynamic backlight control module, a time sequence control module, a liquid crystal driving module, an LCD panel, a backlight driving module and an LED backlight module, wherein the dynamic backlight control module is connected with the decoding module and is used for receiving an image RGB grey scale signal, carrying out gamma correction on the RGB grey scale signal and statistics on the average value and the standard deviation, calculating to obtain the backlight adjusted value, calculating a backlight brightness signal according to the reference brightness value which is preset or input by a user, and outputting the backlight brightness signal to the backlight driving module to drive the LED backlight module to lighten the LCD panel. The invention also discloses the corresponding image signal processing method. The device and the method can effectively reduce the power consumption, increases the contrast, avoids the situation of ultra-low backlight brightness when the image is monochrome image with less standard deviation, and improves the display effect.

Description

A kind of liquid crystal indicator and image-signal processing method

Technical field

The present invention relates to field of liquid crystal display, in particular, a kind of liquid crystal indicator and the disposal route that is applied to the picture signal of this liquid crystal indicator.

Background technology

Liquid crystal display (LCD), with advantages such as its volume are little, lightweight, progressively is applied to each production, sphere of life.Because LCD is passive demonstration, itself be not irradiative, so a back light unit of LCD needs show image as its light source by the light seen through.

Traditional LCD display device has two significant shortcomings: one, power consumption is high.The application LCD electronic product in, the energy consumption of LCD account for total energy consumption 30% to 70%, LCD backlight be again its part that consumes electric energy most, traditional LC D generally adopts the CCFL backlight, in whole duration of work, the CCFL backlight is operated at full capacity all the time, so the electric energy power consumption is very large.Two, the contrast deficiency.Because backlight is entirely bright all the time, and LCD can not close unwanted light fully, thus not even the image of black also looks black, the problem that has therefore caused picture contrast to descend.

In order to address the above problem, the LED of usining has been carried out as the full frame dynamic backlight technology of backlight.A kind of method of definite dynamic backlight is to utilize the brightness maximal value of input picture, but the peaked method of this use exists power consumption saving amount little and to noise sensitive issue too.The method of definite dynamic backlight that another is common is to utilize the average brightness of input picture, but this method exists backlight illumination too low when processing darker image, the problem of loss image detail.

Hong Kong applicating technology research institute is in U.S. Pat 20080291153, average brightness and the variance of the histogram calculation image of image have been proposed to utilize, and then obtained the method for adjusted value backlight by average brightness and variance, but it has the too low problem of monochrome image backlight illumination, as, the backlight illumination of the blue image calculated in this way only has 0.4, is presented at LCD when upper, and the excessively dark phenomenon of image clearly.

Therefore, there is defect in prior art, needs to improve.

Summary of the invention

Technical matters to be solved by this invention is for the deficiencies in the prior art, at first a kind of liquid crystal indicator is provided, further refer to and provide a kind of LED of use can carry out the liquid crystal indicator of dynamically adjusting according to the variation of liquid crystal display content as the brightness of backlight and this LED-backlit, also provide the disposal route of data image signal in a kind of liquid crystal indicator, for straight-down negative or edge strip formula liquid crystal indicator backlight.

Technical scheme of the present invention is as follows:

A kind of liquid crystal indicator, comprise decoder module, time-sequence control module, liquid crystal driver module, backlight drive module, liquid crystal panel and LED-backlit module, and it also comprises the dynamic backlight control module; Described dynamic backlight control module is connected with described decoder module, for receiving image RGB grey scale signal, the RGB grey scale signal is carried out to the γ correction, add up its mean value and standard deviation, calculate adjusted value backlight, and, according to pre-set or Benchmark brightness value input, calculate the backlight illumination signal, output to described backlight drive module; Described backlight drive module is connected with described LED-backlit module, for according to described backlight illumination signal, drives described LED-backlit module, illuminates liquid crystal panel.

Described liquid crystal indicator, wherein, described dynamic backlight control module and described decoder module are wholely set.

Described liquid crystal indicator, wherein, described dynamic backlight control module comprises that the picture signal be linked in sequence receives unit, searches unit, statistic unit, computing unit and backlight control unit; Wherein, described picture signal receives unit, and R, G, B grey scale signal for receiving described picture signal, send to the described unit of searching; The described unit of searching, for converting R, G, B grey scale signal to signal R ', G ', B ' after γ proofreaies and correct, send to described statistic unit; Described statistic unit, mean value and standard deviation for difference statistical signal R ', G ', B ', send to described computing unit; Described computing unit, for according to each mean value and each standard deviation, calculate adjusted value T backlight, and adjusted value T backlight sent to described backlight control unit; Described backlight control unit also is connected with described backlight drive module, for according to described adjusted value T backlight and the Benchmark brightness value S that pre-sets, obtains backlight illumination signal BL, sends to the backlight drive module.

Described liquid crystal indicator, wherein, described dynamic backlight control module also comprises user input unit, it is connected with described backlight control unit, for preset reference brightness value S, sends to described backlight control unit; Described backlight control unit, for the Benchmark brightness value S according to described adjusted value T backlight and input, obtains backlight illumination signal BL, sends to the backlight drive module.

Described liquid crystal indicator, wherein, described statistic unit arranges the histogram subelement, for the histogram of difference statistical picture signal R ', G ', B ', obtains mean value and the standard deviation of R ', G ', B ' by each histogram calculation.

Described liquid crystal indicator, wherein, described computing unit arranges linear combination subelement, judgment sub-unit, computation subunit and user and inputs subelement; Described linear combination subelement is for the maximal value X of the linear combination of calculating the mean value of signal R ', G ', B ' and standard deviation; Wherein, the linear combination of arbitrary signal is for after its standard deviation is multiplied by default coefficient, with its mean value and; And, 0<described default coefficient≤1; Described judgment sub-unit is used for judging whether maximal value X is greater than 255, is T=1 is set, otherwise starts described computation subunit; Described computation subunit is for adopting formula T=(1-T _min) X/255+T _min, calculate described adjusted value T backlight; Wherein, T _minfor parameter preset, 0.5≤T _min≤ 0.9; The user inputs subelement for inputting described default coefficient and/or described parameter preset.

Described liquid crystal indicator, wherein, the user inputs subelement and can arrange in the lump with user input unit.

A kind of image-signal processing method, be applied in arbitrary above-mentioned liquid crystal indicator, and it comprises the following steps: A1, reception picture signal R, G, B; A2, respectively picture signal R, G, B are carried out to the γ correction, be converted to signal R ', G ', B '; A3, the mean value that calculates respectively R ', G ', B ' and standard deviation; A4, according to each mean value and each standard deviation, calculate adjusted value T backlight; A5, according to described adjusted value T backlight, and pre-set or the input luminance reference value S, obtain backlight illumination signal BL, be sent to the backlight drive module, drive described LED-backlit module, illuminate liquid crystal panel.

Described image-signal processing method, wherein, steps A 1, to steps A 5, is also carried out following steps A0, pre-sets or inputs luminance reference value S before arbitrary step.

Described image-signal processing method, wherein, the further comprising the steps of A11 of steps A 1, the described picture signal of buffer memory.

Described image-signal processing method, wherein, in steps A 3, respectively by the histogram of statistics R ', G ', B ', calculate mean value and the standard deviation of R ', G ', B '.

Described image-signal processing method, wherein, the maximal value X of the linear combination of concrete following steps: the A41 of execution of steps A 4, the mean value that calculates signal R ', G ', B ' and standard deviation; Wherein, the linear combination of arbitrary signal is for after its standard deviation is multiplied by default coefficient, with its mean value and; And, 0<described default coefficient≤1; A42, judging whether maximal value X is greater than 255, is that T=1 is set, otherwise execution step A43; A43, employing formula T=(1-T _min) X/255+T _min, calculate described adjusted value T backlight; Wherein, T _minfor parameter preset, 0.5≤T _min≤ 0.9.

Described image-signal processing method, wherein, before steps A 41, also perform step A40, input described default coefficient and/or described parameter preset

Described image-signal processing method, wherein, the further comprising the steps of A51 of steps A 5, the described backlight illumination signal of buffer memory BL.

Described image-signal processing method, wherein, in steps A 5, the product that described backlight illumination signal BL is Benchmark brightness value S and adjusted value T backlight.

The method that adopts such scheme, the present invention to adopt full frame dynamic backlight to adjust, the image shown is as required regulated the brightness of backlight, and backlight illumination can move with figure, thereby can the decrease power consumption, improves the contrast of LCD demonstration image.

Further, less image or the smaller monochrome image of standard deviation for average brightness, control by rational parameter, just can obtain desirable adjusted value, avoids the situation that occurs that backlight illumination is too low, thereby obtain better display effect.Solved the defect existed in the prior art.

The accompanying drawing explanation

Fig. 1 is the schematic diagram of prior art;

Fig. 2 is the structural representation of the embodiment of the present invention 1;

Fig. 3 is the structural representation of the embodiment of the present invention 2;

Fig. 4 is the process flow diagram of image-signal processing method of the present invention;

Fig. 5 is that picture signal of the present invention is processed the histogram obtained.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

Embodiment 1

As depicted in figs. 1 and 2, the present embodiment provides a kind of liquid crystal indicator, comprise decoder module 90, dynamic backlight control module 100, time-sequence control module (timing controller, also claim the T-CON plate) 110, liquid crystal driver module 120, liquid crystal panel 130, backlight drive module 140 and LED-backlit module 150, annexation and the function of above-mentioned decoder module 90, time-sequence control module 110, liquid crystal driver module 120, backlight drive module 140, liquid crystal panel 130 and LED-backlit module 150 belong to prior art, as shown in Figure 1, do not repeat them here.Following emphasis is described dynamic backlight control module 100.

As shown in Figure 2, dynamic backlight control module 100 is connected with decoder module 90, certainly in order to reduce costs, also dynamic backlight control module 100 can be integrated in decoder module 90, as shown in dotted line frame in Fig. 2, that is, an example is that dynamic backlight control module 100 is wholely set with decoder module 90.

Decoder module 90 is for receiving picture signal, according to various different interface types, above-mentioned data image signal can comprise VGA, HDMI, AV, the signals such as CABLE, and image is done to certain processing, and as motion compensation, convergent-divergent etc., then with corresponding interface shape, the picture signal that will process such as the FPD-Link interface shape passes to dynamic backlight control module 100.The picture signal that dynamic backlight control module 100 was processed through decoder module for reception, the described data image signal of full frame performance analysis, and dynamically adjust backlight brightness data according to analysis result.For example, described dynamic backlight control module is connected with described decoder module, receive image RGB grey scale signal, the RGB grey scale signal is carried out to the γ correction, add up its mean value and standard deviation, calculate adjusted value backlight, and according to pre-set or Benchmark brightness value input, calculate the backlight illumination signal, output to described backlight drive module; Described backlight drive module is connected with described LED-backlit module, and for according to described backlight illumination signal, backlight brightness data, drive described LED-backlit module, illuminates liquid crystal panel.It should be noted that, dynamically adjust the backlight illumination method and can adopt any particular algorithms known by the technical staff to be calculated.Dynamic backlight control module 100 is to backlight drive module 140 and time-sequence control module 110 output backlight brightness data and liquid crystal greyscale data, time-sequence control module 110 is connected with liquid crystal driver module 120, for according to the liquid crystal greyscale data, producing the corresponding time sequence control signal, and pass to liquid crystal driver module 120, and then drive liquid crystal panel 130.Backlight drive module 140 is connected with LED-backlit module 150, for according to backlight brightness data driving LED backlight module 150, illuminates liquid crystal panel 130.

Embodiment 2

On the basis of upper example, the present embodiment provides a kind of liquid crystal indicator, as shown in Figure 3, dynamic backlight control module 100 comprises that the picture signal be linked in sequence receives unit 101, searches unit 102, statistic unit 103, computing unit 104, and backlight control unit 106.

Wherein, this picture signal receives unit 101 and searches unit 102 and be connected, and R, G, B grey scale signal for receiver, video one frame image signal, send to and search unit 102.Search unit 102 and be connected respectively with picture signal reception unit 101 and statistic unit 103, R, G, B grey scale signal are converted to signal R ', G ', B ', and signal R ', G ', B ' are sent to statistic unit 103 after γ proofreaies and correct.

Statistic unit 103 respectively with search unit 102 and be connected with computing unit 104, for mean value and the standard deviation of calculating respectively signal R ', G ', B ', and each mean value and each standard deviation are sent to computing unit 104.

Computing unit 104 is connected with backlight control unit 106 with statistic unit 103 respectively, calculates adjusted value T backlight, and adjusted value T backlight is sent to backlight control unit 106.

Backlight control unit 106 is connected with computing unit 104 and backlight drive module 140 respectively, for receiving the adjusted value T backlight of computing unit 104 inputs, according to the Benchmark brightness value S pre-seted, obtain backlight illumination signal BL simultaneously, send to backlight drive module 140.Backlight drive module 140 is connected with backlight control unit 106 and LED-backlit module 150 respectively, receives backlight illumination signal BL, and driving LED backlight module 150, illuminate liquid crystal panel 130.

Perhaps, an example is that dynamic backlight control module 100 can also comprise user input unit 105.User input unit 105 is connected with backlight control unit 106, for to its input reference brightness value S.The user can change basic brightness value within any working time of display device, or the Benchmark brightness value also can be inputted from decoding deck within any working time of display device.

Like this, backlight control unit 106 is connected with computing unit 104, user input unit 105 and backlight drive module 140 respectively, be used for receiving the adjusted value T backlight of computing unit 104 inputs and the Benchmark brightness value S of user input unit input, obtain backlight illumination signal BL, send to backlight drive module 140.Backlight drive module 140 is connected with backlight control unit 106 and LED-backlit module 150 respectively, receives backlight illumination signal BL, and driving LED backlight module 150, illuminate liquid crystal panel 130.

Another example is that described statistic unit arranges the histogram subelement, for the histogram of difference statistical picture signal R ', G ', B ', obtains mean value and the standard deviation of R ', G ', B ' by each histogram calculation.Adopting the method for statistics with histogram, for above-mentioned each example, can be a kind of useful additional project.

Another example is that, on above-mentioned each routine basis, described computing unit arranges linear combination subelement, judgment sub-unit, computation subunit and user and inputs subelement; Described linear combination subelement is for the maximal value X of the linear combination of calculating the mean value of signal R ', G ', B ' and standard deviation; Wherein, the linear combination of arbitrary signal is for after its standard deviation is multiplied by default coefficient, with its mean value and; And, 0<described default coefficient≤1; Described judgment sub-unit is used for judging whether maximal value X is greater than 255, is T=1 is set, otherwise starts described computation subunit; Described computation subunit is for adopting formula T=(1-T _min) X/255+T _min, calculate described adjusted value T backlight; Wherein, T _minfor parameter preset, 0.5≤T _min≤ 0.9; The user inputs subelement for inputting described default coefficient and/or described parameter preset.The user inputs subelement can input described default coefficient and described parameter preset simultaneously; Also can only input described default coefficient or described parameter preset; Storing sub-units can also be set, for storing each mean value, each standard deviation, maximal value X, numerical value 255, default coefficient, parameter preset etc., so that other subelements call these data.

For example, when having user input unit, the user inputs subelement and can arrange in the lump with user input unit.

Embodiment 3

The present embodiment provides a kind of image-signal processing method, is applied in above-mentioned arbitrary routine liquid crystal indicator, and it comprises the following steps.

A1, reception picture signal R, G, B; For example, the further comprising the steps of A11 of steps A 1, the described picture signal of buffer memory.

A2, respectively picture signal R, G, B are carried out to the γ correction, be converted to signal R ', G ', B ';

A3, the mean value that calculates respectively R ', G ', B ' and standard deviation; For example, respectively by the histogram of statistics R ', G ', B ', calculate mean value and the standard deviation of R ', G ', B '.

A4, according to each mean value and each standard deviation, calculate adjusted value T backlight.

For example, the concrete following steps of carrying out of steps A 4:

The maximal value X of the linear combination of A41, the mean value that calculates signal R ', G ', B ' and standard deviation; Wherein, the linear combination of arbitrary signal is for after its standard deviation is multiplied by default coefficient, with its mean value and; And, 0<described default coefficient≤1;

A42, judging whether maximal value X is greater than 255, is that T=1 is set, otherwise execution step A43;

A43, employing formula T=(1-T _min) X/255+T _min, calculate described adjusted value T backlight; Wherein, T _minfor parameter preset, 0.5≤T _min≤ 0.9.

And for example, before steps A 41, also perform step A40, input described default coefficient and/or described parameter preset.

A5, according to described adjusted value T backlight, and pre-set or the input luminance reference value S, obtain backlight illumination signal BL, be sent to the backlight drive module, drive described LED-backlit module, illuminate liquid crystal panel.For example, the product that described backlight illumination signal BL is Benchmark brightness value S and adjusted value T backlight.And for example, the further comprising the steps of A51 of steps A 5, the described backlight illumination signal of buffer memory BL.

For example, the arbitrary step for steps A 1 to steps A 5, before carrying out this step, can also carry out following steps A0, pre-set or input luminance reference value S.The user can change basic brightness value within any working time of display device, or the Benchmark brightness value also can be inputted from decoding deck within any working time of display device.

Embodiment 4

A kind of method that the present embodiment provides picture signal to process, be applied in above-mentioned each routine liquid crystal indicator, and with reference to figure 2 and Fig. 4, the method comprises the following steps.

A1, picture signal receive unit 101 and receive R, G, B grey scale signal, and this grey scale signal is sent to and searches unit 102; For example, the further comprising the steps of A11 of steps A 1, picture signal receive the described picture signal of unit 101 buffer memory, thereby the output of picture signal are synchronizeed with the output of adjusted value backlight.

A2, search unit 102 and proofread and correct by γ, convert this grey scale signal R, G, B to signal R ', G ', B ', and signal R ', G ', B ' are sent to statistic unit 103, its computing formula is:

R '=R ^γformula (1)

G '=G ^γformula (2)

B '=B ^γformula (3)

Wherein for R, G, the γ value that the γ of B proofreaies and correct can be different, and span is [2,3], i.e. 2≤γ≤3, for example, and for R, G, the γ value of the γ correction of B, be respectively 2.1,2.2,2.25.

A3, statistic unit 103 calculate mean value and the standard deviation of signal R ', G ', B ', are designated as respectively R ' _avg, G ' _avg, B ' _avgand R ' _std, G ' _std, B ' _std.Then, statistic unit 103 sends to computing unit 104 by the mean value and the standard deviation that calculate.

Suppose that a frame picture has N pixel, be numbered respectively 1,2.....N, the signal of each pixel is respectively R ₁', G ₁', B ₁'; R2 ', G ₂', B ₂'; ... ..R _n', G _n', B _n',

R ' _avg=(R ₁'+R2 '+... R _n')/N formula (4)

G ' _avg=(G ₁'+G2 '+... G _n')/N formula (5)

B ' _avg=(B ₁'+B2 '+... B _n')/N formula (6)

${R^{,}}_{\mathrm{std}}={\left[\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{({R_i}^{\&prime;}-{R^{\&prime;}}_{\mathrm{avg}})}^2\right]}^{1/2}$ Formula (7)

${G^{,}}_{\mathrm{std}}={\left[\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{({G_i}^{\&prime;}-{G^{\&prime;}}_{\mathrm{avg}})}^2\right]}^{1/2}$ Formula (8)

${B^{,}}_{\mathrm{std}}={\left[\frac{1}{N}\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{({B_i}^{\&prime;}-{B^{\&prime;}}_{\mathrm{avg}})}^2\right]}^{1/2}$ Formula (9)

A4, computing unit 104 calculate adjusted value T backlight, and adjusted value T backlight is sent to backlight control unit 106.In computing unit, at first calculate the maximal value of the linear combination of the mean value of signal R ', G ', B ' and standard deviation, be designated as X,

X＝Max(R’ _avg+a0*R’ _std；G’ _avg+a0*G’ _std；B’ _avg+a0*B’ _std)

Wherein, the a0 numerical range be (0,1], i.e. 0<a0≤1.

Secondly, according to X, calculate brightness adjustment value T, formula is as follows:

T=(1-T _min) X/255+T _minformula (10)

T wherein _minbe preassigned parameter, numerical range is [0.5,0.9], i.e. 0.5≤T _min≤ 0.9.When the X value is greater than 255, the T value is fixed as 1.

From above formula, when showing black image, the gray scale of each pixel is 0 o'clock, X=0, substitution formula (10), T=T _min, the brightness value while having reduced to greatest extent blank screen, make screen enough dark, thereby improved contrast.

When image is the less monochrome image of standard deviation, by reasonably pre-seting parameter T _min, can avoid the situation that occurs that backlight illumination is too low.

A5, backlight control unit 106 are according to adjusted value T backlight, and the Benchmark brightness value S of the Benchmark brightness value S pre-seted or user's input, calculate backlight illumination signal BL:

BL=S * T formula (11)

Backlight control unit 106 sends to backlight drive module 140 by backlight illumination signal BL, and driving LED backlight module 150 sends the backlight of given luminance, illuminates liquid crystal panel 130.

For example, the further comprising the steps of A51 of steps A 5, backlight drive module 140 buffer memory backlight illumination signal BL, thus the output of picture signal is synchronizeed with the output of adjusted value backlight.

For example, in above-mentioned arbitrary image-signal processing method, steps A 1, to steps A 5, is also carried out steps A 0, user input unit 105 before arbitrary step and is pre-seted luminance reference value S.User input unit sends to backlight control unit 106 by S, for calculating backlight illumination signal BL.

Embodiment 5

On the basis of embodiment 4, in steps A 3, statistic unit is by the histogram subelement, and the histogram of statistical signal R ', G ', B ', can as shown in Figure 3, obtain mean value and the standard deviation of signal R ', G ', B ' by this histogram calculation respectively.

Wherein, suppose number of times that the i level gray scale of R ', G ' corresponding to 0 to 255 grade of gray scale, B ' occurs N respectively _ri, N _gi, N _bi, mean value:

${R^{,}}_{\mathrm{avg}}=\frac{\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{\mathrm{iN}}_{\mathrm{Ri}}}{\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Ri}}}$ Formula (12)

${G^{,}}_{\mathrm{avg}}=\frac{\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{\mathrm{iN}}_{\mathrm{Gi}}}{\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{\mathrm{NG}}_i}$ Formula (13)

${B^{,}}_{\mathrm{avg}}=\frac{\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{\mathrm{iN}}_{\mathrm{Bi}}}{\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{\mathrm{NB}}_i}$ Formula (14)

${R^{,}}_{\mathrm{std}}={[\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{(i-{R^{\&prime;}}_{\mathrm{avg}})}^2{N}_{\mathrm{Ri}}/\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Ri}}]}^{1/2}$ Formula (15)

${G^{,}}_{\mathrm{std}}={[\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{(i-{G^{\&prime;}}_{\mathrm{avg}})}^2{N}_{\mathrm{Gi}}/\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Gi}}]}^{1/2}$ Formula (16)

${B^{,}}_{\mathrm{std}}={[\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{(i-{B^{\&prime;}}_{\mathrm{avg}})}^2{N}_{\mathrm{Bi}}/\underset{i=0}{\overset{255}{\mathrm{\&Sigma;}}}{N}_{\mathrm{Bi}}]}^{1/2}$ Formula (17)

Calculate R ' _avg, G ' _avg, B ' _avgand R ' _std, G ' _std, B ' _stdafterwards, the step computing successively according to A4, A5 and A6 in embodiment 3, until obtain backlight illumination signal BL, output to backlight drive module 140, and driving LED backlight module 150 illuminates liquid crystal panel 130.Be not described in detail in this.

By picture signal being done to above-mentioned full frame dynamic backlight, process, the method significantly reduces power consumption and improves contrast.In addition, when calculating backlight illumination, considered average brightness and the standard deviation of image simultaneously.Because average brightness and standard deviation are statistics, so, even noise is arranged on image, also can not affect the adjusted value backlight finally calculated.For average brightness and all less image of standard deviation, the parameter T in dominated formulate (10) _min, just can obtain desirable adjusted value, not there will be the too low situation of backlight illumination.

Should be understood that, for those of ordinary skills, can be improved according to the above description or convert, and all these improvement and conversion all should belong to the protection domain of claims of the present invention.

Claims (10)

1. a liquid crystal indicator, comprise liquid crystal driver module, backlight drive module, liquid crystal panel and LED-backlit module, it is characterized in that, also comprises decoder module, time-sequence control module and dynamic backlight control module;

Described dynamic backlight control module is connected with described decoder module, for receiving image RGB grey scale signal, the RGB grey scale signal is carried out to the γ correction, add up its mean value and standard deviation, calculate adjusted value backlight, and, according to pre-set or Benchmark brightness value input, calculate the backlight illumination signal, output to described backlight drive module;

Described backlight drive module is connected with described LED-backlit module, for according to described backlight illumination signal, drives described LED-backlit module, illuminates liquid crystal panel;

Described dynamic backlight control module comprises that the picture signal be linked in sequence receives unit, searches unit, statistic unit, computing unit and backlight control unit; Wherein,

Described picture signal receives unit, and R, G, B grey scale signal for receiving described picture signal, send to the described unit of searching;

The described unit of searching, for converting R, G, B grey scale signal to signal R ', G ', B ' after γ proofreaies and correct, send to described statistic unit;

Described statistic unit, mean value and standard deviation for difference statistical signal R ', G ', B ', send to described computing unit;

Described computing unit, for according to each mean value and each standard deviation, calculate adjusted value T backlight, and adjusted value T backlight sent to described backlight control unit;

Described backlight control unit also is connected with described backlight drive module, for according to described adjusted value T backlight and the Benchmark brightness value S that pre-sets, obtains backlight illumination signal BL, sends to the backlight drive module;

Described statistic unit arranges the histogram subelement, for the histogram of difference statistical picture signal R ', G ', B ', obtains mean value and the standard deviation of R ', G ', B ' by each histogram calculation;

Described computing unit arranges linear combination subelement, judgment sub-unit, computation subunit and user and inputs subelement;

Described linear combination subelement is for the maximal value X of the linear combination of calculating the mean value of signal R ', G ', B ' and standard deviation; Wherein, the linear combination of arbitrary signal is for after its standard deviation is multiplied by default coefficient, with its mean value and; And, 0<described default coefficient≤1;

Described judgment sub-unit is used for judging whether maximal value X is greater than 255, is T=1 is set, otherwise starts described computation subunit;

Described computation subunit, for adopting formula T=(1-Tmin) X/255+Tmin, is calculated described adjusted value T backlight; Wherein, Tmin is parameter preset, 0.5≤Tmin≤0.9;

The user inputs subelement for inputting described default coefficient and/or described parameter preset.

2. liquid crystal indicator according to claim 1, is characterized in that, described dynamic backlight control module and described decoder module are wholely set.

3. liquid crystal indicator according to claim 2, is characterized in that, described dynamic backlight control module also comprises user input unit, and it is connected with described backlight control unit, for pre-seting Benchmark brightness value S, sends to described backlight control unit;

Described backlight control unit, for the Benchmark brightness value S according to described adjusted value T backlight and input, obtains backlight illumination signal BL, sends to the backlight drive module.

4. an image-signal processing method, be applied to, in the arbitrary described liquid crystal indicator of claims 1 to 3, it is characterized in that, comprises the following steps:

A1, reception picture signal R, G, B;

A2, respectively picture signal R, G, B are carried out to the γ correction, be converted to signal R ', G ', B ';

A3, the mean value that calculates respectively signal R ', G ', B ' and standard deviation;

A4, according to each mean value and each standard deviation, calculate adjusted value T backlight;

A5, according to described adjusted value T backlight, and pre-set or the input luminance reference value S, obtain backlight illumination signal BL, be sent to the backlight drive module, drive described LED-backlit module, illuminate liquid crystal panel;

The concrete following steps of carrying out of steps A 4:

The maximal value X of the linear combination of A41, the mean value that calculates signal R ', G ', B ' and standard deviation; Wherein, the linear combination of arbitrary signal is for after its standard deviation is multiplied by default coefficient, with its mean value and; And, 0<described default coefficient≤1;

A42, judging whether maximal value X is greater than 255, is that T=1 is set, otherwise execution step A43;

A43, employing formula T=(1-T _min) X/255+T _min, calculate described adjusted value T backlight; Wherein, T _minfor parameter preset, 0.5≤T _min≤ 0.9.

5. image-signal processing method according to claim 4, is characterized in that, the further comprising the steps of A11 of steps A 1, the described picture signal of buffer memory.

6. image-signal processing method according to claim 4, is characterized in that, steps A 1, to steps A 5, was also carried out following steps A0, pre-seted or input luminance reference value S before arbitrary step.

7. image-signal processing method according to claim 4, is characterized in that, in steps A 3, respectively by the histogram of statistics R ', G ', B ', calculates mean value and the standard deviation of R ', G ', B '.

8. image-signal processing method according to claim 4, is characterized in that, before steps A 41, also performs step A40, inputs described default coefficient and/or described parameter preset.

9. image-signal processing method according to claim 4, is characterized in that, the further comprising the steps of A51 of steps A 5, the described backlight illumination signal of buffer memory BL.

10. image-signal processing method according to claim 4, is characterized in that, in steps A 5, and the product that described backlight illumination signal BL is Benchmark brightness value S and adjusted value T backlight.

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